Question

This must be embarrassingly easy, but I can’t find the solution: I have a text file with data in this form:

| 1 | 1 | A | X |
|   | 2 | A | Z |
|   |   | B | Y |

I would like to process this data with Lua, so I need to have it in a structured (nested) table like this (I hope the indentation comes out right):

t = {
    ['1'] =
    {  
        ['1'] = 
        {
            {
                { ['A'] = 'X' },
            },
        },
        ['2'] = 
        {
            {
                { ['A'] = 'Z' },
                { ['B'] = 'Y' },
            },
        },
    },
}

But I can’t figure out how to go from A to B. The structure is already kind of there, but how can I read it into Lua?

Answer 1

This will definitely do the task for you.

tTable = {}
OldIDX, OldIDX2, bSwitched, bSwitched2 = 0, 0, false, false

for str in io.lines("txt.txt") do
    local _, _, iDx, iDex, sIdx, sVal = str:find( "^%| ([%d|%s]?) %| ([%d|%s]?) %| (%S?) %| (%S?) %|$" )
    if not tonumber(iDx) then iDx, bSwitched = OldIDX, true end
    if not tonumber(iDex) then iDex, bSwitched2 = OldIDX2, true end
    OldIDX, OldIDX2 = iDx, iDex
    if not bSwitched then
        tTable[iDx] = {}
    end
    if not bSwitched2 then
        tTable[iDx][iDex] = {}
    end
    bSwitched, bSwitched2 = false, false
    tTable[iDx][iDex][sIdx] = sVal
end

NOTE

The only thing you can change in the code is the name of the file. 🙂

EDIT

Seems like I was wrong, you did need some changes. Made them too.